_STACK SEGMENT STACK            ;8088宏汇编程序
    DW   64 DUP (?)             ;定义堆栈段
_STACK ENDS 
CODE    SEGMENT                 ;定义代码段
ASSUME CS:CODE,SS:_STACK

START: MOV  CX,0005H
       MOV  DI,3500H
A1:    MOV  BL,0FFH
       MOV  AL,[DI]
       CMP  AL,3AH
       JNB  A2
       SUB  AL,30H
       JC  A2
       MOV  BL,AL
A2:    MOV  AL,BL
       MOV  [DI+0AH],AL
       INC  DI
       LOOP  A1
A3:    JMP  A3

CODE   ENDS
    END     START